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#1 2006-09-30 04:48:21

kelvinli1988
Guest

Help Needed Asap!!!

how do u do this???

dump2.jpg

#2 2006-09-30 05:46:07

polylog
Member
Registered: 2006-09-28
Posts: 162

Re: Help Needed Asap!!!

You need to add the two fractions:

find the common denominator!

the process is the same as this process for adding fractions with 'ugly denominators':

3/23 + 7/57  is:

3 * 57  +  7 * 23
--------------------
        23 * 57

Does that help?

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#3 2006-09-30 06:10:28

kelvinli1988
Guest

Re: Help Needed Asap!!!

wat is the common denominator but????

#4 2006-09-30 06:41:26

polylog
Member
Registered: 2006-09-28
Posts: 162

Re: Help Needed Asap!!!

Do you know how to add algebraic fractions? For example try this:

1/m + 1/n

If not, ask and I can explain it.

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#5 2006-09-30 06:57:14

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Help Needed Asap!!!

polylog wrote:

Here is another example that should help:

Say we want to add these:

1/n + 1/m

To add two fractions they must have the *same denominators*.

To make these denominators the same, we can multiply them by n and m :

1/(n * m) + 1/(m * n)

BUT, we can't just put in those factors, because we have changed the values of the fractions.

So, we have to multiply the numerators also, to make sure that the fractions are not changed:

(1 * m)/(n * m) + (1 * n)/(m * n)

notice that:

(1 * m)/(n * m) = 1/n

and:

(1 * n)/(m * n) = 1/m

just like before. But now they have the same denominators! So we can add them! :

(1 * m)/(n * m) + (1 * n)/(m * n) = (m + n) / (m * n)

so we can see that :

1/n + 1/m = (m + n)/mn


Your question requires the same procedure, just with messier expressions.

polylog tried to post this, but instead made it into a report.


Why did the vector cross the road?
It wanted to be normal.

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#6 2006-09-30 11:06:03

polylog
Member
Registered: 2006-09-28
Posts: 162

Re: Help Needed Asap!!!

oops! sorry about that, i thought that post was lost, but i must have just used the wrong button wink

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